Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Where in the cell can ribosomes be found, Where in the cell can ribosomes b...

Where in the cell can ribosomes be found? What is the main biological function of ribosomes? Ans) Ribosomes can be found free in the cytoplasm, adhered to the outer side of the

How are ecological interactions classified, Q. How are ecological interacti...

Q. How are ecological interactions classified? Ecological interactions are classified as interspecific or intraspecific interactions and as harmonious or inharmonious interacti

Give some examples of cloning and molecular biology, Examples of cloning an...

Examples of cloning and molecular biology cloning may produce heterozygous individuals (as mother was heterozygous) and suggests a way to get pure breeding cats molecu

The first carbon having 2 h atoms, Given a polymer backbone of H-C-C with t...

Given a polymer backbone of H-C-C with the first carbon having 2 H atoms attached and the 2nd carbon with 3 atoms attached, a bond with a water molecule attaches to the left H atom

Hiv, The chances of transmission in female is mor than males

The chances of transmission in female is mor than males

Rna secondary structure, Most  RNA  molecules  are  single-stranded  but  a...

Most  RNA  molecules  are  single-stranded  but  an  RNA  molecule  should  hold regions  that  can  form  complementary   base  pairing  where  the  RNA  strand loops  back  on  i

Determine which is most stable, Hydrogen ( H) has 1 electron, carbond ( c) ...

Hydrogen ( H) has 1 electron, carbond ( c) has 6 electrons ; oxygen ( O) has electrons, Nitrogen ( n) HAS 7 electrons. Use the octet rule to determine which of the following is mos

Enumerate about the colour vision defects, Enumerate about the colour visio...

Enumerate about the colour vision defects Acquired colour vision defects can occur afkr damage to the optic nerve or macula and in some cases, because of blue blindness in old

Light microscopy, Light microscopy: Microscopy started with light micr...

Light microscopy: Microscopy started with light microscopes using visible light to illuminate the objects, the most used and familiar microscope is called compound light micro

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd